4d multimodal nanomedicines made of nonequilibrium au-fe alloy nanoparticles

TORRESAN, VERONICA; BADOCCO, DENIS; SELLONI, ANNABELLA; FERNANDEZ VAN RAAP, MARCELA B.; SPINELLI, ANTONELLO E.; FORRER, DANIEL; PASTORE, PAOLO; CORAL, DIEGO; BUSATO, ALICE; AMENDOLA, VINCENZO; GUADAGNINI, ANDREA; CASARIN, MAURIZIO; CEOLIN, MARCELO; MARZOLA, PASQUINA

ACS NANO

AMER CHEMICAL SOC

Año: 2020 vol. 14 p. 12840 - 12853

1936-0851

Several examples of nanosized therapeutic and imaging agents have been proposed to date, yet for most of them there is a low chance of clinical translation due to longterm in vivo retention and toxicity risks. The realization of nanoagents that can be removed from the body after use remains thus a great challenge. Here, we demonstrate that nonequilibrium gold-iron alloys behave as shape-morphing nanocrystals with the properties of self-degradable multifunctional nanomedicines. DFT calculations combined with mixing enthalpy-weighted alloying simulations predict that Au-Fe solid solutions can exhibit self-degradation in an aqueous environment if the Fe content exceeds a threshold that depends upon element topology in the nanocrystals. Exploiting a laserassisted synthesis route, we experimentally confirm that nonequilibrium Au-Fe nanoalloys have a 4D behavior, that is, the ability to change shape, size, and structure over time, becoming ultrasmall Au-rich nanocrystals. In vivo tests show the potential of these transformable Au-Fe nanoalloys as efficient multimodal contrast agents for magnetic resonance imaging and computed X-ray absorption tomography and further demonstrate their self-degradation over time, with a significant reduction of long-term accumulation in the body, when compared to benchmark gold or iron oxide contrast agents. Hence, Au-Fe alloy nanoparticles exhibiting 4D behavior can respond to the need for safe and degradable inorganic multifunctional nanomedicines required in clinical translation.